336 Glossary 



Blas'to-der'-mic Ves'-i-cle. A hollow sphere, formed from the segmented 



egg of a mammal, which becomes attached to or embedded within the 



wall of the uterus. 

 Blas'-to-pore. The mouth of a gastrula. 

 Blas'-tu-la. A mass of cells, usually in the shape of a hollow sphere, 



formed by repeated divisions (cleavages) of an egg. 

 Blending Inheritance. <Galton's term for that kind of inheritance in 



which the characters of the parents seem to blend in the offspring. 

 Brach-y-dac'-ty-lism. The condition of having abnormally short fingers 



or toes. 

 Cell. The fundamental unit of structure and function in all living things. 

 Cen'-tro-some. The body at the center of radiations in a dividing cell. 

 Ceph'-a-lo-pods. A class of mollusks which includes the squid, cuttle- 

 fish and devil-fish. 

 Cer'-e-bral Gang'-li-on. The brain- of an invertebrate animal. 

 Character. Any feature or property of an organism. 

 Chor'-da. A cellular rod in vertebrate embryos which forms the basis of 



the backbone. 

 Chor'-date. A member of the highest phylum of the animal kingdom, 



including all animals having a chorda or backbone. 

 Cho'-ri-on. A tough membrane around an egg secreted by surrounding 



cells. 

 Chro'-ma-tin. The deeply staining substance of the nucleus. 

 Chro'-mo-meres. The linear series of chromatin bodies in a chromosome. 

 Chro'-mo-somes. Deeply staining bodies found in the nucleus at the 



time of indirect division. 

 Chromosomal Vesicles. The swollen chromosomes of inter-division 



stages. 



Cil'-i-a. Minute protoplasmic threads on the surface of a cell which pro- 

 duce movements in the surrounding medium by waving back and 

 forth. 



Class. The chief sub-division of a phylum. 



Cleav'-age. The division of the egg cell into many cells after fertilization. 



Clep-si'-ne. A genus of leeches. 



Coe'-lom. The body cavity. 



Continuous variation. A series of minute variations. 



Correlative differentiation. Differentiation due chiefly to the interac- 

 tion of different parts of an organism. 



Cre-pid'-u-la. A genus of marine gastropods. 



"Criss-Cross" Inheritance. Morgan's term for that kind of inheritance 

 in which maternal characters are transmitted to sons and paternal 

 ones to daughters. 



